<template>
    <div>
        <el-select :value="valueTitle" :clearable="clearable" @clear="clearHandle">
            <el-option :value="valueTitle" :label="valueTitle">
                <el-tree
                    id="tree-option"
                    ref="selectTree"
                    :accordion="accordion"
                    :data="options"
                    :props="props"
                    :node-key="props.value"
                    :default-expanded-keys="defaultExpandedKey"
                    :default-checked-keys="defaultExpandedKey"
                    :current-node-key="valueId"
                    @node-click="handleNodeClick"
                ></el-tree>
            </el-option>
        </el-select>
    </div>
</template>


<script>
export default {
    name: 'el-tree-select',
    props: {
        /* 配置项 */
        props: {
            type: Object,
            default: () => {
                return {
                    value: 'id', // ID字段名
                    label: 'title', // 显示名称
                    children: 'children' // 子级字段名
                };
            }
        },
        /* 选项列表数据(树形结构的对象数组) */
        options: {
            type: Array,
            default: () => {
                return [];
            }
        },
        /* 初始值 */
        value: {
            type: String,
            default: () => {
                return '';
            }
        },
        departName: {
            type: String,
            default: () => {
                return '';
            }
        },
        /* 可清空选项 */
        clearable: {
            type: Boolean,
            default: () => {
                return true;
            }
        },
        /* 自动收起 */
        accordion: {
            type: Boolean,
            default: () => {
                return true;
            }
        }
    },
    data() {
        return {
            valueId: this.value, // 初始值
            valueTitle: '',
            defaultExpandedKey: []
        };
    },
    mounted() {
        this.initHandle();
    },
    methods: {
        // 初始化值
        initHandle() {
            if (this.valueId) {
                console.log('initHandle', this.valueId);
                //console.log('initHandle valueTitle', this.$refs.selectTree);
                this.$refs.selectTree.setCurrentKey(this.valueId); // 设置默认选中
                console.log('initHandle setCurrentKey', this.$refs.selectTree);
                this.defaultExpandedKey = [this.valueId]; // 设置默认展开
                //this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[this.props.label]; // 初始化显示
                this.valueTitle = this.departName;
            }
            this.$nextTick(() => {
                let scrollWrap = document.querySelectorAll('.el-scrollbar .el-select-dropdown__wrap')[0];
                let scrollBar = document.querySelectorAll('.el-scrollbar .el-scrollbar__bar');
                scrollWrap.style.cssText = 'margin: 0px; max-height: none; overflow: hidden;';
                scrollBar.forEach(ele => (ele.style.width = 0));
            });
        },
        // 切换选项
        handleNodeClick(node) {
            console.log('handleNodeClick', node);
            this.valueTitle = node[this.props.label];
            console.log('handleNodeClick valueTitle', this.valueTitle);
            this.valueId = node[this.props.value];
            this.$emit('handleTreeClick', node);
            this.defaultExpandedKey = [];
        },
        // 清除选中
        clearHandle() {
            this.valueTitle = '';
            this.valueId = '';
            this.defaultExpandedKey = [];
            this.clearSelected();
            this.$emit('handleTreeClick', '');
        },
        /* 清空选中样式 */
        clearSelected() {
            let allNode = document.querySelectorAll('#tree-option .el-tree-node');
            allNode.forEach(element => element.classList.remove('is-current'));
        }
    },
    watch: {
        value() {
            this.valueId = this.value;
            console.log('value',this.value)
            this.initHandle();
        }
    }
};
</script>



<style scoped>
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item {
    height: auto;
    max-height: 274px;
    padding: 0;
    overflow: hidden;
    overflow-y: auto;
}
.el-select-dropdown__item.selected {
    font-weight: normal;
}
ul li >>> .el-tree .el-tree-node__content {
    height: auto;
    padding: 0 20px;
}
.el-tree-node__label {
    font-weight: normal;
}
.el-tree >>> .is-current .el-tree-node__label {
    color: #409eff;
    font-weight: 700;
}
.el-tree >>> .is-current .el-tree-node__children .el-tree-node__label {
    color: #606266;
    font-weight: normal;
}
</style>